Flexible container bags are mainly used in order to be filled with and transport individual substances (various mining-and-manufacturing feedstock, food or agricultural materials such as fertilizers). In the flexible container bags, contents (objects to be transported or stored) are charged and saved from a charging opening, and the contents are discharged from a discharge opening. Both the charging opening and the discharge opening are typically bound by closing ropes. During charging, in many cases, the charging is performed in a state where a charging opening of a flexible container bag is opened from the beginning. Therefore, inconvenience rarely occurs in the work of untying the closing rope. In contrast, during discharge in which contents are discharged in order to use the contents in factories/farms or the like, particularly in a case where the closing rope that closes the discharge opening of a lower surface of the flexible container bag is firmly tightened, there is a problem that substantial time is taken to loosen the closing rope in manual work and working efficiency drops. On the other hand, in a case where the closing rope is loosely tightened, there is a problem in that contents may leak out from the discharge opening due to factors such that the discharge opening is widened by the pressing of contents and the closing rope is easily untied. In such a case, if work is performed under the flexible container bag filled with contents in a state where the flexible container bag is hung up or in a state where the discharge opening of the flexible container bag is exposed, there is also a problem in that there is a concern about danger caused by dropping of the contents.
An example of a Highland lock (registered trademark) as a rope fixture of a conventional bag opening binding tool is illustrated in FIG. 12A and FIG. 12B. The Highland lock 40 is constituted by four components including a main body 41, a toothed stopper 42, a hollow shaft 43, and a release string 44. For example, polypropylene is used for these components. For example, a wire net braid 47 having 5 mmϕ diameter is used as a string that opens and closes a drawstring bag 45. First, the wire net braid 47 is passed through a string passing-through hole 46 that allows a string formed around a bag opening of the drawstring bag 45 to pass therethrough, and two tip portions of the wire net braid 47 are taken out to the outside from the string passing-through hole 46. Next, the two tip portions of the wire net braid 47 are taken out to the outside through the main body 41. Although a cavity is formed in the main body 41, the width of the cavity is wide at an outlet and becomes narrower from the outlet toward the interior. The two tip portions of the wire net braid 47 are arranged along both side surfaces of the main body 41. Next, the toothed stopper 42 is inserted from the outlet side of the main body 41. If the toothed stopper 42 is put into the interior, the wire net braid 47 is pressed against and fixed to both internal side walls of the main body 41 by the toothed stopper 42. Next, the hollow shaft 43 is thrusted into the toothed stopper 42 from a slit 48 provided in the main body 41. Next, the release string 44 is passed through the hollow shaft 43. In this state, the wire net braid 47 is held while being fixed to the internal side walls of the main body 41. If the release string 44 is pulled in the direction of an arrow, the toothed stopper 42 can be pulled in the direction and the two tip portions of wire net braid 47 can be released from the pressing applied by the toothed stopper 42, can be separated from the internal side walls of the main body 41, and can be freely moved in a longitudinal direction of the wire net braid 47.
Another example of a rope fixture of a conventional bag opening binding tool is illustrated in FIG. 13A and FIG. 13B (refer to Patent Document 1). A Y-shaped fastener 51 is used for a portion of a pet pulling leash 50. An example in which a lead 52 that constitutes a loop at a portion serving as a collar is inserted into the Y-shaped fastener 51 from two places of a Y-shaped upper portion and two portions of the lead inserted from the two places are gathered together into one bundle at a Y-shaped lower portion is illustrated. Here, the lead 52 is fixed to the Y-shaped fastener 51 by a frictional force between the lead 52 and the Y-shaped fastener 51. Additionally, in a rope pressing supporter 55 provided at a handle portion 53, the two tips of the lead 52 are pressed against the internal side walls and fixed to the handle portion 53 by rotating a knob 54.
Additionally, as another example of the rope fixture of the conventional bag opening binding tool, a lever mechanism as seen in a buckle for a belt is used, and the closing rope is pressed and fixed by a lever having a saw-toothed projection provided at a tip thereof.
However, in such a conventional rope binding tool, since the rope is merely pressed against the side walls or the like and is fixed in one place, there is a problem in that the rope is loosened and untied after binding. Additionally, if the tips of the rope is passed through a tube or the like for a rope slider and is firmly tied during binding, there is a problem in that, when a heavy load is applied to a knot, the knot becomes tight and is difficult to be untied during releasing.